The current trial was conducted to study the effect of maturity on the potential nutritive value, methane production and condensed tannin of Sanguisorba minor hay. Sanguisorba minor hay harvested at three different maturity stages (pre- flowering, flowering and seeding stages). Sanguisorba minor hay was shade dried and analyzed for chemical composition. Gas and methane productions of Sanguisorba minor hay were determined at 24 h incubation time. Maturity had a significant effect (P<0.05) on the chemical composition, gas production, methane production metabolisable energy (ME) and organic matter digestibility (OMD). Neutral detergent fiber (NDF) and acid detergent fiber (ADF) of Sanguisorba minor hay increased with advancing maturity whereas crude protein (CP) and ash content decreased. The CP contents of Sanguisorba minor hay varied between 6.7 and 20.7%. The NDF and ADF contents of Sanguisorba minor hay ranged from 36.2 to 54.5 and 17.4 to 36.2 % respectively. The condensed tannin content of Sanguisorba minor hay varied with maturity between 0.4 and 1.6 % and decreased (P<0.05) with increasing maturity. The gas and methane production at 24 h incubation ranged from 32.2 to 43.5 ml and 4.6 to 6.5 ml respectively and decreased (P<0.05) after flowering. The ME and OMD of Sanguisorba minor ranged from 7.0 and 9.3 MJ/kg DM and 46.9 to 63.2% respectively and decreased (P<0.05) with each increment of the maturity. In conclusion, maturity had a significant effect on the nutritive value of Sanguisorba minor hay. The nutritive value of Sanguisorba minor decreased with increased maturity. It can be suggested that Sanguisorba minor should be grazed or harvested at pre-flowering and flowering stage since these stage provides hay with high ME and CP for ruminant.